Posted by Bruce Clarke on June 13, 1999 at 02:20:01:
In Reply to: Engine oil posted by Craig Solem on June 12, 1999 at 15:56:28:
If you search the internet for the phrase "motorcycle oil" you'll find some FAQs that answer the question pretty thoroughly. My take on this is that any "name brand" oil is good but over time collects moisture, dirt, etc. Synthetic oil keeps its viscosity longer than 'natural' but if you run it longer than you're just keeping that dirt/water trapped in the oil running in the engine longer.
I use Castrol 10w40 GTX oil in my Savage, and change it either every four months regardless of mileage. The manual says to change the oil and filter every 6000 KM - this strikes me as way too long between changes for an air-cooled single.